This invention relates to the manufacture of twisted pair and single transmission line wires wherein the effective electrical diameter of the primary conductor is increased thereby providing a desired characteristic impedance along the length of the wire and allowing the wires to be terminated using standard termination equipment. This invention is particularly useful for solderless wrap connections to printed circuit boards or panels and for twisted wire and single wire interconnections.
Prior to this invention, transmission wire with a low impedance (less than 100 ohms) was not available for use with standard termination equipment. Typically, a primary conductor with a diameter greater than 20 mils had to be selected in order to achieve a low characteristic impedance. Only a thin wall of insulation could be wrapped around the primary conductor without increasing the characteristic impedance. Since only a thin wall of insulation could be used, there was poor cut-through resistance of this outer wall of insulation and other stripping difficulties.
Because of the low cut-through and abrasion resistance of these thin outer insulation walls, it was often necessary to apply a protective jacket over the wire. This further aggravated the stripping problem as the jacket first had to be removed during termination. During removal, the primary conductor is frequently damaged by the stripping blades. These difficulties have been substantially eliminated by the present invention.